[UnLimiTeD]

So, due to some discussions in the past, I know that Infection should work just fine on metavariants, and stats-wise, one should just calculate the difference between base and infected state, and then add that onto the stats of the meta variant. No biggie.
But what about the fluff?

Let's assume for a bit a Fomorian Troll.
Being the unlucky bloke that he is (He was born a Fomorian, after all, can't do much worse than that), he is bitten, and becomes infected; what kind is of no importance in this matter.
Now, practically all Troll Infections state that they modify the dermal armour in some way. But what if the troll has no dermal armour? How would it influence him/her?

No, let's rewind time.
Our Troll, let's call him Brad, surges, gaining Granite Skin. As he has no natural dermal Armour, that works out. Then he is infected. What happens now?

[Patrick Goodman]

He's a Fomoraig dzoo-noo-qua; he gains +1 dermal armor on top of his other stuff (but underneath his hair...mostly). It's all additive; if he doesn't have it, he gets it)

At least that's how I'm reading it right now, with a substantial sleep-deprivation issue going on. When I've had some rest, I might be reading it differently and this could change. But I'm pretty sure that's right. Ping me again this weekend and I'll try to make sure I'm not blowing smoke up your ass.

[UnLimiTeD]

I take your silence as an agreement with your previous statement (Or you have one of those pesky "lives" and didn't have time yet, but hey, where would we get if we just assumed?) .
So, to sum it up:

An Infected Troll gets +1 Dermal Armour, for a total of 2.
An Infected Fomoraig gets +1 Dermal Armour, for a total of 1.
An Infected surged Fomoraig gets +1 Dermal Armour, for a total of 5.
An Infected Giant gets +1 Dermal Armour, for a total of 3 (Very tough bark, I assume?).

One last question:
If you have granite shell, and you then get +1 Dermal Armour (Just fluffwise, Harvesters just get +2 Armour and no one really knows how that manifests), is that just + 1 Armour that is used when calculating incoming damage regularly, or os that +1 hardened armour, which would in turn mean it would not stack with worn armour?

[Reaver]

I take your silence as an agreement with your previous statement (Or you have one of those pesky "lives" and didn't have time yet, but hey, where would we get if we just assumed?) .
So, to sum it up:

An Infected Troll gets +1 Dermal Armour, for a total of 2.
An Infected Fomoraig gets +1 Dermal Armour, for a total of 1.
An Infected surged Fomoraig gets +1 Dermal Armour, for a total of 5.
An Infected Giant gets +1 Dermal Armour, for a total of 3 (Very tough bark, I assume?).

One last question:
If you have granite shell, and you then get +1 Dermal Armour (Just fluffwise, Harvesters just get +2 Armour and no one really knows how that manifests), is that just + 1 Armour that is used when calculating incoming damage regularly, or os that +1 hardened armour, which would in turn mean it would not stack with worn armour?

Normal armor.

[UnLimiTeD]

So infected circumvent the "Doesn't stack with any other dermal alteration"?

[Reaver]

I can't even find the write up for granite shell anymore to referr back to...

[UnLimiTeD]

Run Faster, in the Surge Chapter, page 113/114.

Dermal Alteration is incompatible with any
other natural or artificial skin modification.

On reading this again, it might actually mean active modifications, not including natural subdermal armour. Hmm, that'd indeed simplify things.

[Patrick Goodman]

Formorian, not fomoraig. That's the Infected Type II for trolls. Other than that, I was not in fact blowing smoke up your ass.

As to the granite shell question...for Infected trolls, +1 of that is going to be bony, lumpy, deformed troll armor. Infection for trolls is nasty. And unfortunate. But mostly nasty.

Harvesters get their armor by way of hard, durable hide. Gnawers get theirs from a more even calcification of the dermal tissue. I think gnawers still get some armor; it's been Monday in big red flashing letters, so I could again be misremembering.

It's normal armor, not hardened. If it had been hardened armor, it would have been noted as such (there are two distinct powers, after all).

The key word in Dermal Alteration is "modification," which strongly implies active things like cyber or bioware. I can't remember if it got discussed much during the writing phase, but the deformity-causing bone nuggets that pop up on trolls were definitely meant to ignore that. Yeah, they can be an exceptionally armored tank...but he's, at best, grotesque.

I think that covers all the questions. And yeah, that whole "life" thing is a pain in the ass sometimes.

[UnLimiTeD]

Thank you very much.
Your answers always provide insight and clarity I wouldn't get otherwise. 
Much appreciated.

[Reaver]

So infected circumvent the "Doesn't stack with any other dermal alteration"?

After reading Granite shell again, i think what the writer means by "but does not fully stack with other worn armor" is that granite shell doesn't turn any more armor worn into hardened armor...

So if you had granite shell (4 HA) and a long coat (12 A), you suddenly do not have 16 hardened armor. - they specifically make note that you get 2 auto hits from the ability.

I read that to mean, in the above case, you would have 12 armor + 2 auto hits on your damage resistance test.

So yea, the bone growth on a troll would still add armor, just not hardened armor.

[The Wyrm Ouroboros]

I personally would not care about the character's vampiric/SURGE interaction meaning that he gets an additional level of hardened armor; I honestly wouldn't want the headache of the paperwork, though it'd certainly be easy enough to simply say, 'You have X automatic successes'.  On the other hand, a dzoo-no-quah with granite skin is going to draw aaaaaall the gun-fires, so I wouldn't be so graceless as to not let him have a free +1 success, because he's still probably going to get pounded into unconsciousness ...

[Patrick Goodman]

A good point.

[PJ]

Speaking of Infection and Metavariants...

What happens regarding combos that have similar weaknesses and/or cancel flaws?  Specifically, I'm thinking of a Nocturna Ghoul.  Nocturna have Allergy: Sunlight-Mild and Unusual Hair: body fur.  Ghouls lose all hair and have Sunlight-Moderate.

Do you have to buy off the Hair and Mild Allergy?  Does the Allergy upgrade?  Ignore it?  There may be other combos, but that is what came to mind.

[Patrick Goodman]

They'd lose the hair and upgrade the allergy. Not feeling like doing the math at the moment to see if they'd get Karma back or not. Probably would. Might be a GM call.

I know. Not the definitive answer. Sorry. Brain's kinda spongy at the moment and it doesn't look to be improving in the immediate future.

EDIT: Updates and killing lots of typos. Stupid phone keyboard.

[The Wyrm Ouroboros]

Depends on whether or not you're just smacking them with the infection.  Presuming character generation, in this case I'd go mean on them - pay all the points, no karma back.  Sux2BU, as my dear Uncle Ernie always says.  (With one such sent to rampage across a planet.)